The purpose of the game is to discard all cards. Spot cards count their rank while faces (jack, queen, king) are valued at ten points. If the total of at least two consecutive cards equals 10, 20 or 30 , they are discarded. The cards sequence is treated as a loop. So in sequence 3, 9, 2 , 4, 3 you can discard 3,4,3.

This image is a schematic representation, not a screenshot from the game. Screenshots are platform specific. You can see screenshots in the store.